1. Field
The present invention relates to a polyimide precursor composition, a method for manufacturing a polyimide molded body, and a polyimide molded body.
2. Description of the Related Art
A polyimide resin is a material having high durability and excellent heat resistance, and is widely used in electronic material applications.
As a method for manufacturing a molded body of the polyimide resin, a method in which a polyimide precursor composition in which a polyamic acid which is a precursor thereof is dissolved in an aprotic polar solvent such as N-methyl-2-pyrrolidone (NMP) is coated on a substrate, and by a heat treatment, the resultant product is dried and imidized, whereby a polyimide molded body is manufactured is known (for example, see U.S. Pat. No. 4,238,528).
In addition, in the manufacture of the polyimide precursor composition, it is also known that a process in which a polyimide precursor resin is polymerized in an aprotic polar solvent such as NMP, and the polyimide precursor resin is taken out by reprecipitation, and dissolved in water by applying an amine salt is performed (for example, see JP-A-08-120077, JP-A-08-015519, JP-A-2003-13351 and JP-A-08-059832).
Moreover, examples of the solvent to dissolve the polyamic acid include dimethyl acetamide (DMAc), dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (γ-BL), and the like in addition to NMP (for example, see Journal of Polymer Science, Macromolecular Reviews, Vol. 11, P. 164 (1976)).
On the other hand, as the aprotic polar solvent, a water-soluble alcohol-based solvent compound and/or a water-soluble ether-based solvent compound is used, and specifically, it is known that by adding a tertiary amine to a reaction system in a mixed solvent of tetrahydrofuran (THF) and methanol, or THF and water, a polyimide precursor composition is obtained without precipitation (for example, see JP-A-08-157599).
It is also known that in the coexistence of imidazole having a specific structure as an amine compound, a water-based polyimide precursor composition is obtained by polymerizing the polyimide precursor in water (for example, see JP-A-2012-036382).